A typical method of testing electronic devices coupled to an electronic module or circuit board is with the use of a test fixture. The test fixture typically has a bed of nails (spring probes) upon which the circuit board is mounted for testing. The spring probes make electrical contact with test points (access pins or ports) on the circuit board. In operation, the test fixture applies select signals to a select test point on the circuit board and monitors a response to the select signals at another select test point of the circuit board. Approximately 80 to 90 percent of the electronic devices on the circuit board can be tested with a typical test fixture.
The testing of a clock (or oscillator) on a circuit board is typically done by applying power to a select test point that is electrically coupled to the oscillator and taking a frequency measurement at another test point that is coupled to an output of the oscillator. If the frequency measured is a frequency that is expected, the oscillator is verified as working. However, if the measured frequency is not what is expected, the oscillator is not working properly.
Test fixtures are very expensive to purchase. Moreover, economically it is difficult to justify purchasing a test fixture if the volume of circuit boards produce is relatively low. In addition, the cost is doubled if the manufacture of the circuit boards takes place in two different locations and the testing needs to take place at both locations. It is desired in the art to have an efficient, non-expensive method of testing an oscillator on a circuit board.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an improved method of testing an oscillator on a circuit board.